Improve parse speed by switching from regexps to simple string operations.
50k short flags
before: 11ms, 11ms, 13ms, 11ms, 17ms
after: 6ms, 5ms, 6ms, 5ms, 8ms
50k abbreviations
before: 97ms, 114ms, 120ms, 111ms, 107ms
after: 39ms, 37ms, 51ms, 36ms, 36ms
50k long flags
before: 27ms, 26ms, 24ms, 24ms, 28ms
after: 15ms, 19ms, 19ms, 15ms, 15ms
50k long options with =
before: 27ms, 26ms, 27ms, 24ms, 26ms
after: 15ms, 19ms, 19ms, 15ms, 15ms
diff --git a/lib/src/parser.dart b/lib/src/parser.dart
index 2a41f17..fe88687 100644
--- a/lib/src/parser.dart
+++ b/lib/src/parser.dart
@@ -9,10 +9,6 @@
import 'arg_results.dart';
import 'option.dart';
-final _soloOpt = RegExp(r'^-([a-zA-Z0-9])$');
-final _abbrOpt = RegExp(r'^-([a-zA-Z0-9]+)(.*)$');
-final _longOpt = RegExp(r'^--([a-zA-Z\-_0-9]+)(=(.*))?$');
-
/// The actual argument parsing class.
///
/// Unlike [ArgParser] which is really more an "arg grammar", this is the class
@@ -127,14 +123,17 @@
/// We treat this differently than collapsed abbreviations (like "-abc") to
/// handle the possible value that may follow it.
bool parseSoloOption() {
- var soloOpt = _soloOpt.firstMatch(current);
- if (soloOpt == null) return false;
+ // Hand coded regexp: r'^-([a-zA-Z0-9])$'
+ // Length must be two, hyphen followed by any letter/digit.
+ if (current.length != 2) return false;
+ if (!current.startsWith('-')) return false;
+ var opt = current.substring(1, 2);
+ if (!_isLetterOrDigit(opt.codeUnitAt(0))) return false;
- var option = grammar.findByAbbreviation(soloOpt[1]);
+ var option = grammar.findByAbbreviation(opt);
if (option == null) {
// Walk up to the parent command if possible.
- validate(
- parent != null, 'Could not find an option or flag "-${soloOpt[1]}".');
+ validate(parent != null, 'Could not find an option or flag "-$opt".');
return parent.parseSoloOption();
}
@@ -153,12 +152,28 @@
/// (like "-abc") or a single abbreviation with the value directly attached
/// to it (like "-mrelease").
bool parseAbbreviation(Parser innermostCommand) {
- var abbrOpt = _abbrOpt.firstMatch(current);
- if (abbrOpt == null) return false;
+ // Hand coded regexp: r'^-([a-zA-Z0-9]+)(.*)$'
+ // Hyphen then at least one letter/digit then zero or more
+ // anything-but-newlines.
+ if (current.length < 2) return false;
+ if (!current.startsWith('-')) return false;
+
+ // Find where we go from letters/digits to rest.
+ var index = 1;
+ while (
+ index < current.length && _isLetterOrDigit(current.codeUnitAt(index))) {
+ ++index;
+ }
+ // Must be at least one letter/digit.
+ if (index == 1) return false;
// If the first character is the abbreviation for a non-flag option, then
// the rest is the value.
- var c = abbrOpt[1].substring(0, 1);
+ var lettersAndDigits = current.substring(1, index);
+ var rest = current.substring(index);
+ if (rest.contains('\n') || rest.contains('\r')) return false;
+
+ var c = lettersAndDigits.substring(0, 1);
var first = grammar.findByAbbreviation(c);
if (first == null) {
// Walk up to the parent command if possible.
@@ -168,22 +183,22 @@
} else if (!first.isFlag) {
// The first character is a non-flag option, so the rest must be the
// value.
- var value = '${abbrOpt[1].substring(1)}${abbrOpt[2]}';
+ var value = '${lettersAndDigits.substring(1)}$rest';
setOption(results, first, value);
} else {
// If we got some non-flag characters, then it must be a value, but
// if we got here, it's a flag, which is wrong.
validate(
- abbrOpt[2] == '',
+ rest == '',
'Option "-$c" is a flag and cannot handle value '
- '"${abbrOpt[1].substring(1)}${abbrOpt[2]}".');
+ '"${lettersAndDigits.substring(1)}$rest".');
// Not an option, so all characters should be flags.
// We use "innermostCommand" here so that if a parent command parses the
// *first* letter, subcommands can still be found to parse the other
// letters.
- for (var i = 0; i < abbrOpt[1].length; i++) {
- var c = abbrOpt[1].substring(i, i + 1);
+ for (var i = 0; i < lettersAndDigits.length; i++) {
+ var c = lettersAndDigits.substring(i, i + 1);
innermostCommand.parseShortFlag(c);
}
}
@@ -213,21 +228,33 @@
/// Tries to parse the current argument as a long-form named option, which
/// may include a value like "--mode=release" or "--mode release".
bool parseLongOption() {
- var longOpt = _longOpt.firstMatch(current);
- if (longOpt == null) return false;
+ // Hand coded regexp: r'^--([a-zA-Z\-_0-9]+)(=(.*))?$'
+ // Two hyphens then at least one letter/digit/hyphen, optionally an equal
+ // sign followed by zero or more anything-but-newlines.
- var name = longOpt[1];
+ if (!current.startsWith('--')) return false;
+
+ var index = current.indexOf('=');
+ var name = index == -1 ? current.substring(2) : current.substring(2, index);
+ for (var i = 0; i != name.length; ++i) {
+ if (!_isLetterOrDigitOrHyphen(name.codeUnitAt(i))) return false;
+ }
+ var value = index == -1 ? null : current.substring(index + 1);
+ if (value != null && (value.contains('\n') || value.contains('\r'))) {
+ return false;
+ }
+
var option = grammar.options[name];
if (option != null) {
args.removeFirst();
if (option.isFlag) {
- validate(longOpt[3] == null,
- 'Flag option "$name" should not be given a value.');
+ validate(
+ value == null, 'Flag option "$name" should not be given a value.');
setFlag(results, option, true);
- } else if (longOpt[3] != null) {
+ } else if (value != null) {
// We have a value like --foo=bar.
- setOption(results, option, longOpt[3]);
+ setOption(results, option, value);
} else {
// Option like --foo, so look for the value as the next arg.
readNextArgAsValue(option);
@@ -302,3 +329,14 @@
'"$value" is not an allowed value for option "${option.name}".');
}
}
+
+bool _isLetterOrDigit(int codeUnit) =>
+ // Uppercase letters.
+ (codeUnit >= 65 && codeUnit <= 90) ||
+ // Lowercase letters.
+ (codeUnit >= 97 && codeUnit <= 122) ||
+ // Digits.
+ (codeUnit >= 48 && codeUnit <= 57);
+
+bool _isLetterOrDigitOrHyphen(int codeUnit) =>
+ _isLetterOrDigit(codeUnit) || codeUnit == 45;
